NdBaMn₂O_5+δ layered perovskite as an active cathode material for solid oxide fuel cells

摘要

A layered perovskite, NdBaMnO (NBMO), was synthesized by solid state reaction method in air. Rietveld analysis of X-Ray Diffraction (XRD) data showed the material crystallizing in orthorhombic symmetry ( space group). Scanning electron microscopy (SEM) was used to check the morphology and, the analysis of the micrographs exhibited a porous structure with in-situ growth of nanoparticles. Electrochemical Impedance Spectroscopy (EIS) measurements from 600 °C to 800 °Cshows the highest conductivity value of 1.17 × 10 S/cm obtained at 800 °C with low activation energy (E) of 0.3 eV in air. In 5% H/Ar gas mixture, the conductivity and activation energy values were 1.97 × 10−2 S/cm and 0.4 eV, respectively at 800 °C. The DC conductivity measurements also showed that this material is highly conductive in air with a conductivity value of 0.75 S/cm at 850 °C. Dual chamber fuel cell measurements on Ni-YSZ/YSZ/NBMO cell using 5% H/Ar as fuel (from 700 °C to 800 °C) showed a maximum power density of 0.202 W/cm at 800 °C. The relatively high conductivity of the material in air and low activation energy makes it a potential candidate as cathode for solid oxide fuel cells.